The present invention generally relates to instruments for bending rods.
A wide variety of instruments are known in the art for bending rods. Some bending instruments utilize a three-post bending combination in association with a handle or lever combination. In such a device, the center post is generally located at the pivot of the two-arm device and each of the two outer posts are mounted on an arm so as to be pivotable therewith about the center post. Application of manually applied force to the handles or lever mechanism generally causes the outer posts to orbit about the center post in such a manner as to bend a rod-like article positioned between the center post and the outer posts about the center posts. An example of a bending tool utilizing a three-post bending combination is described in U.S. Pat. No. 4,474,046 to Cook. Another is described in U.S. Pat. No. 4,304,117 to Rawson. This type of bending tool utilizes leverage against a post-member in order to help effect the bending.
Another style of device utilizes two Bending Tubes, such as product number 1292-98 sold by Zimmer, Inc. in Warsaw, Ind. These 1292-98 Bending Tubes are tubular, straight rods with an interior channel in each. One end of a straight rod is placed in one channel of one instrument and the other end of the rod is placed in the channel of the other instrument. An external key or lever may be threaded through a hole in the wall of each instrument to press against the rod in the channel to secure the rod's position in the channel and prevent it from sliding within the channel. Manual pressure is then applied to the handles of both instruments to swing the handle ends toward each other and thus bend the rod. However, with the two straight instruments it is difficult to initiate the bend or get the bend in the rod started.